A child restraint system, also referred to as a child car seat, is used for safely transporting a child within an automotive vehicle, so as to minimize the risk of injury to the child in the event of an accident. A typical child restraint system comprises a polymeric shell defining a compartment that is sized and shaped for receiving the child. The compartment is lined with a cushion to enhance comfort. A harness is provided to restrain the child within the compartment. The harness comprises belts that extend through slots in the shell. To optimize safety, it is desired to locate the slots adjacent the shoulders of the child. As the child grows, however, the child's shoulders may extend beyond the slots, thereby reducing the effectiveness of the harness in safely restraining the child. For this reason, the child car seat commonly includes multiple sets of slots located to accommodate children of varying size. That is, the child car seat includes a first set of slots positioned proximate to the shoulders of a smaller child, and a second set of slots positioned proximate to shoulders of a larger child. One problem is that, as the child grows, the adult operator, typically a parent, may not be aware that the first slots are no longer recommended for the child and that the harness needs to be adjusted to the second slots.
Therefore, a need exists for a child restraint system that includes a control unit that determines the size of a child and the location of the harness, and alerts the parent when the harness is not properly adjusted for the child.